Pick-up trucks have been used for many years as work vehicles. These trucks typically have a rectangular open bed. The bed has side walls that permit large objects to be carried. Although this type of bed is versatile, it has limitations. Because the bed is open, it affords no protection from the elements. Items stored there are subject to water damage from rain, for example. Also, the beds of most trucks do not have any fixed storage capacity. Thus, anything stored in the bed must be secured or it may shift during transit. Finally, the open bed provides no security to items stored there. Tools, tool boxes and other items are kept in plain view and can easily be taken from the truck.
Many ideas have addressed storage problems of pick-up truck beds. A solution for keeping the elements out of the bed uses a canvas or vinyl cover that snaps around the side walks. This cover does keep the elements out of the bed, however, it reduces the practical space that can be employed. Moreover, the cover is time consuming to remove and to put on.
Many styles of tool boxes, for example are available. These boxes typically are secured behind the truck cab and have lockable doors for access. An example of such a tool box is found in U.S. Pat. No. 4,946,215 to Taylor. In this design, a "T" shaped box is employed. The "T" shape allows the box to fit between the wheel wells in the truck bed. The Taylor device had a hinged, lockable cover and is designed to be fastened down to the truck bed. The device is the same height as the side walls of the truck. Although this device is well designed, it has two flaws. First, it fits in one-half of the truck bed, which effectively reduces the amount of storage space available. Second, the box is the height of the side walls. Although this provides a lot of storage space within the box, it limits the storage space significantly. With this box in place, for example, it is difficult to carry uncut sheets of plywood in the bed.
A second group of storage units can be found in U.S. Pat. No. 2,784,027 to Temp, U.S. Pat. No. 4,575,731 to Knaack et al., and U.S. Pat. No. 4,733,898 to Williams. All of these devices disclose some type of pull out drawer units. The temp design shows a pull out drawer that has a number of different sized storage boxes, and even a water tank and sink. The drawer unit has a fold down support to hold the unit up when it is pulled out. The Knaack et al. design also uses a pull out drawer. This drawer, however, has a number of slots so that the drawer can be partitioned, rather than having fixed partitions. This unit is also lockable. Finally, Williams design has a pair of drawers that pull out of the center of his unit. Besides the drawers, the top of the unit fits over the entire truck bed, including the wheel wells. The Williams design also has four top opening storage boxes formed around the wheel wells. All of these box designed are made to be lower than the truck side walls, thereby leaving ample room for flat storage on top. As good as these devices are, they are not designed to ballast the truck for winter driving conditions. Moreover, unless a person needs long pullout drawers, the storage options are limited to lots of small parts and tools. Anything larger than the drawers, or of an odd shape, can not readily be kept in the drawers.
Besides the storage problem, discussed above, pick-up trucks also have a problem with handling during winter. Most pick-up trucks are rear-wheel drive. Unless these trucks are loaded, they have a tendency to "fishtail" on icy roads. To correct this problem, many truck owners simply add sand bags to the bed of the truck to increase traction. Sand bags are heavy and messy and may shift unless secured. As a result, although sand bags do help, they can be troublesome and even dangerous.
A number of devices have been invented to address the ballast problem directly. These designs are found in U.S. Pat. No. 4,796,914 to Raynor, U.S. Pat. No. 4,971,356, to Cook, U.S. Pat. No. 5,172,953 to Chamberlain, and U.S. Pat. No. 5,330,227 to Anderson. The Raynor design is a bed liner, that conforms to the shape of the truck bed. In this design, liquid ballast can be added as needed to provide additional weight if desired. The bed liner has no protected or secure storage areas. The problem with this design is two fold. First, although bed liners are useful to keep the bed from being damaged, they do nothing to solve the storage problems discussed above. Second, using liquid as ballast in a northern climate is not practical. The liquid will freeze and damage the bed liner. Moreover, the density of most liquids is low compared to other materials, such as sand, requiring much more liquid than sand to achieve the same ballasting effect. The Cook patent teaches use of weights shaped like puzzle pieces as ballast. The idea is to interlock several puzzle pieces to form a block of ballast that covers the truck bed. By using different combinations of blocks, different sized beds may be covered. The problems here are the complexity of assembly and that the blocks are no better than sandbags-just dead weight in the back of the truck. The Chamberlain patent teaches a low level, formed bed liner that has an inner cavity that can be filled with ballast. This design also uses wooden platforms to carry objects and to protect the ballast. The problem here is that there is no protection or security for the stored items. The bed liner protects the bed, but does nothing for the objects carried in the truck. Finally, the Anderson design teaches the use o#long rectangular storage tubes that can hold ballast material. The tubes run the length of the bed and have access doors so that the ballast material can be added. The problem with this design is that filling the tubes is difficult. The tubes are six to eight feet long and have a small door for filling. The tubes must be angled to ensure that the ballast material fills the entire tube (or some type of ram must be used to push the fill to the back of the tube). Again, this design produces nothing more than dead weight in the back of the truck, with no storage or security provisions.